from The Century Dictionary and Cyclopedia

Etymologies

observing +‎ -ly (Wiktionary)

Examples

She will need to hold her breath, I said, reading on, if she is to do it; for women are so suspicious of any interest that has not some obvious motive behind it, so terribly accustomed to concealment and suppression, that they are off at the flicker of an eye turned observingly in their direction.

By reading the afore-mentioned three columns horizontally and _onwards_, instead of vertically and _downwards_ "in the old trite vulgar way," it was contended that much mirth might observingly be distilled from the most unhopeful material, as "_blind Chance_" frequently brought about the oddest conjunctions, and not seldom compelled _sub juga aenea_ persons and things the most dissimilar and discordant.

As it is not supposable that the mind of man has just become observingly active in the last few centuries, absolute evidence of purer and deeper reason than we have been able to present, stand recorded on the faces of many valuable "lost arts" which we have never been able to equal.